1. Field of the Invention.
This invention relates to control devices, and particularly to a control device that translates axial movement of a member into rotary movement of an associated member, with axial movement being effected with fluid pressure.
2. Description of the Prior Art.
The prior art related to the subject matter of the invention disclosed herein is believed to be found in Class 74, sub-classes 109, 110 and 422. A search in this area has revealed the existence of the following U.S. Pat. Nos.:
______________________________________ 2,842,972 2,857,628 2,885,902 2,958,263 3,349,927 3,524,436 3,525,102 3,786,938 3,848,759 4,392,631 4,520,994 4,561,592 4,541,293 4,662,557 ______________________________________
The structures disclosed in the patents listed above without exception are dissimilar from the structure disclosed and claimed herein. The prior art is replete with patents that utilize many different methods and structures for translating motion in one direction to a different type of motion in an opposite or transverse direction, or even translating axial motion into rotary motion of an associated element. However, we have not found any of these structures to be as simple and economical to manufacture and operate, or to produce the close tolerances of movement that are required in many industries, as is true with the subject matter of this invention.
In many industries, control devices are used to position an element, say a machine element, to perform a given function. Frequently, the movement of such a machine element is controlled in terms of the direction of movement and extent of movement by a computer. Accordingly, one of the important objects of the invention is the provision of a control device that is fluid operated and which accurately transforms linear movememt of one element to rotary movement of an associated element.
Because of the precision that is required to be maintained in the manufacture of many different devices, it is important that control devices associated with a machining function work within very close tolerances and in cooperation with whatever type of tool is used to perform the machining function. Accordingly, another important object of the invention is the provision of a control device in which such close tolerances are inherent from the specialized construction of the control device.
While we have indicated above that a control mechanism such as the one disclosed herein is useful in positioning a tool to effect a machining operation on a work piece, it is also an object of the invention that the control device of this invention be utilized to control the position of a work piece in relation to a stationary machine tool. Thus, it is contemplated that in one aspect of this invention, a work piece may be mounted directly on the control device, and the work piece moved from one location to another by operation of the control device, whereupon a predetermined operation may be performed on the work piece in the location to which it is moved.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however, that the invention is not limited to the embodiment illustrated and described, since it may be embodied in various forms within the scope of the appended claims.